1. Field of the Invention
The present invention relates to a reproduction apparatus for carrying out reproduction from a recording medium capable of recording image information and additional auxiliary information associated in some way with the image information.
2. Related Art
Various recording media on which it is possible to record both audio and video information in association with each other are known, including, for example, the still video floppy disc, whose format was determined in the Still Video Conference (hereinafter termed simply "floppy" for convenience). In this format (floppy format), image signals are recorded, one circular track for each field, or two tracks for each frame, while the audio information is time-compressed and, increasing the frequency region of the audio signal within that of the image signal, the audio signal is recorded using the same system as for the image signal. In the case of the audio signal, one track has four sectors (#0-#3), and there are four types of methods of using those sectors. In type one, recording continues from a sector to the next sector in the same track. In type two, recording is ended in the track in question and picks up again in the first sector (#0) of the next track. In type three, the sequence of audio signals is terminated. In type four, a sector of that track remains unused, or sectors of that track are the remainder of sectors which are used as types one to three. As shown in FIG. 6, in each sector a start flag is provided before the time-compressed audio signal, and after the signal, an end flag. By means of the combination of start flag and end flag, it is possible to identify and thus to discriminate which of the four types is being used.
An audio signal sequence starts from a type one sector and is completed in a type three sector. FIG. 5 shows an example of four tracks in which one audio sequence is recorded, with each involved sector being shown.
In each sector is included a control code for the purpose of controlling the audio signal sequence. Table 1 shows the contents of the control code. By means of this control code, it is possible to reproduce a sequence of audio signals as continuous sound. Again, it is also possible to assign one still image to each track, and to reproduce the audio while the still image is being reproduced.
To reproduce an audio signal from the floppy, it is necessary to know the control code of the audio signal in advance. In order to effect the reproduction smoothly, it is also necessary to know for each track whether the track is empty, whether it contains an audio signal ("audio track"), whether it contains an image signal ("image signal track"), and, if it is an image signal track, whether it is a high-band or a low-band recording and whether it is a frame or a field, etc. For this purpose, in many conventional systems, upon inserting the floppy a prescan is carried out in which every track is checked and an indication of the contents of each track is stored, and then the system assumes a standby state for awaiting the operator's instructions.
TABLE 1 ______________________________________ Word Data ______________________________________ W0 Track number W1 Track number of initial audio signal of a signal sequence W2 Track number of next audio signal W3 Track number of corresponding image W4 (Reserved) W5 Time axis compression rate W6 Day W7 Month W8 Year ______________________________________
However, such a prescan operation requires typically about twenty seconds and must be carried out, with the consequent cost in time, even if the floppy is one on which only image information is recorded.